Boiler for steam or hot-water heating



(No Model.) 2 Sheets-Sheet l.

W. M. MACKAY. EoILEE EOE STEAM 0E EOT WATEE HEATING.

Patented Oct. 5,1897

NoModel.) 2shee1-.s-sheet2- W. M. MAGKAY. BOILEE EOE STEAM 0E EOT WATERHEATING.

No. 591,236; Patented out. 5,1897.

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UNITED STATEsqV PATENT @Erica WILLIAM M. MAoIrI-IY, or NEWARK, NEWJERSEY, AssIeNoR To TIIE HART a oRoUsE COMPANY, or UTIoA, NEW YORK.

BOILER FORSTEAVIVORl HOT-WATER HEATING.

SPECIFICATION forming part of LettersPatent No. 591,236, dated October5, 1897.

Application iiled March 8, 1897. Serial No. 626,398. (No model.)

T @ZZ whom it may concern:

Be it known that I, WILLIAM M. MACKAY, a citizenof the United States,residing at Newark, county of Essex, State of New Jersey, have inventedcertain new and useful Improvements in Boilers for Steam or Hot-VVaterHeating, fully described and represented in the following specicationand the Vaccompanyin g drawings, forminga part of the same.

This invention relatesto that class of steam or hot-waterfboilers whichis composed of `al series of flat vert-ical sections having a reboxformed by the water-legs of the sections and a hollow fire-arch forwater-circulation extended between the legs at the top of the fire-box.

In the present construction the boiler is formed of suitable capacity byusing the required number of vertical sections, but the sections are notof uniform pattern, as the intermediate sections are slightly differentfrom the front section to control the Inovement of the gases and therear section is Y formed of a water-platel from the level of the grateupward to close the rear end of the fire-box. V

In the present construction the water-legs are extended downward to formthe sides of the ash-box, which is closed at the front end by aboiler-front having fuel-door, ash-door, and cleaning-out door and atthe vrear by a smoke-box containing dampers to vary the draft throughthe fines.

The operation of the construction is described in a boiler for heatingwater, but the same construction may also be used for generating steam,in which case the upper portions of the sections would be filled withsteam instead of water.

Each section is provided with a water-arch at the top, which isconnected with the firearch by vertical water-tubes, and t-lze fire#arches are made the full thickness of the sections over the front partof the tire-box to prevent the ascent ofthe gases, while the firearch inthe sections at the rear of the boiler is notched in the middle upon oneor both sides to permit the gases to rise among the water-tubes. Certainof the water-tubes at opposite sides of the center line are made thefull thickness of the section to form partitions extending nearly to thefront ofthe boiler, to make return-flues at the sides of the boiler,which are connected at their rear ends with Vthe smoke-box.4 The gaseswhich rise 5 5 between the rear sections are thus compelled to moveforwardly among the water-tubes before they can enter the return-fl ueswhich lead them to the srnoke-boxf The invention is especially adaptedfor boil- 6o i ers of rathersmall capacity, in which a largegrate-surface is not desired, but in which con# siderable area isrequired between the watertubes to form the flues for the forward andbackward passage of the gases. To secure such area, I have constructedthe water-arch at thetop of the section considerably longer than thefire-arch which unites the tops of the water-legs, so as to secure therequisite space for fines between the water-tubes, and 7o haveproportioned/che passages which extend from the tops of the water-legsto the top of the section of smaller sectional area than the water-legs,so as to divert into the ire-arch a portion of the water which risesfrom the water-legs. I form the top of water-leg at the endsv of theiireearch with outwardly-projecting Water-chamber, which thus stands atthe junction of the water-legs, the vertical tubes above `the same, andthe fire-arch at 8o one side of the chamber. The enlarged space in suchchambers prevents conflict between the upward and downward currentsentering such chambers,which sometimes occurs in the generation ofsteam., The lire-arch confines the gases to the furnace, excepting atthe rear -part of the boiler, where the lire-arches are notched over themiddle of the furnace to permit the gases to rise upwardly, and certainof thewatentubes at opposite ends of such 9o notches are made the fullthickness of the section to divert the gases into the front sections ofthe boiler, from whence they return to a fire-boxat the rear of theboiler through lateral yiiues over the water-chambers just mentioned.

The invention consists partly in the constructive features of thevdifferent sections, partly in their combination, as shown in thedrawings, and partly in the means for adjust- Ioo ing the dampers withinthesmoke-box.' y

i These improvements will be understood by reference to the annexeddrawings, in which- Figure 1 is a side elevation of a boiler embodyingmy improvements. Fig. 2 is a vertical section of the boiler upon thecenter line transverse to the sections. Fig. 3 is a front elevation ofthe boiler; Fig. 4, a horizontal section on line 4 4 in Fig. S, with thedampers closed and the cranks and their link connection retained uponthe tops of the dam-1 hand side of the center line one of the frontsections of the boiler and at the left side of g the center line one ofthe intermediate seetions. Fig. 9 is a cross-section on line 9 9 in Fig.8, and Fig. l0 is a cross-section on line 5 Fig. ll is a verticalsection across the center of one of the front sections Q of the boiler,and Fig. 12 is a similar section of one of the intermediate sections.

4 fr in Fig. s.

Fig. 13 is a plan, and Fig. 14 an edge view, of the link for adjustingthe damper-cranks.

A designates the water-legs at opposite sides of the ire-box B.Tater-chambers A' are projected outwardly at the tops Vof the water-legsand connected upon their inner sides with a fire-arch having its upperporj tion or body C the full thickness of the section (except wherenotched at the middle portion, as hereinafter described) and its lowerlside formed with `a central water-channel C'.

A water-arch D extends across the top of the section and is connected atits ends with the water-chambers A' by vertical tubes or pasl sages E,and vertical water-tubes F F' F2,with interspaces G G', connect thewater-arch with the fire-arch.

the rear of the boiler.

upward to the ends of the water-arch D. The water-arch is made ofsuilicient capacity to permit the movement of the water through thedifferent water-tubes to the outlet D' upon the middle of thewater-arch, and the {ire-arch is, including the water-channel C' uponits under side, of still greater cross-section to permit a freedistribution of the water to the water-tubes in which the water-currentis most rapid; but the passages E are made of much less capacity thanthe water-arch or fire-arch, so that' the water which rises from thewater-leg into the chamber A' may be di- Fig. 7 is rected into the tubesover the fire, where it will be most effectively heated.

The water-chamber ismade of much greater cross-section than the nre-archto prevent conflict between upward and downward currents entering suchchamber, which sometimes occurs inthe generation of steam, ashereinafter set forth, and especially to permit a free circulation ofwater within the boiler when the external circulation is cutoff withoutchecking the fire, and a downward movement in the passages E is producedby the upward movement in the tubes over the lire.

The variations in the sections are noticeable in Figs. 2 and 4, Fig. 2showing the three front sections S with the tire-arch the full thicknessof the section, while the intermediate sections S' and S2 and the rearsection S3 are notched upon the side of thefire-arch to permit the gasesto pass upwardly into the spaces between the tubes F. Fig. 4 shows thetubes F' next to the passages E of less thickness than the section, likethe tubes F, while the adjoining tubes F2 in all the sections except thetwo at the front are made the full thickness of the section to formpartitions between the -spaces G and G', which ad join the tubes F andF', respectively.

The rear section shown in Figs. 2 and 7 is formed of a water-plate s3,having upon its edges the water-legs A, passages E, and waterarch D,with passages H and I-l' connecting the water-legs at the upper andlower parts of the ash-box B', which is shown in Fig. 2. Verticalwater-passages I are extended within the plate through passage H to thewater-arch D, and the water-chambers A' are provided between thepassages E and the watenlegs, and portions of the tire-arch C areextended inwardly lfrom such chamber, with tubes F' j and F2 extendedupwardly therefrom to the The group of sections constituting th eboileris connected at the top with a header N and pipe connection n, attachedto lthe `outlet D' upon the top of each section, and by mani-'g folds O,connected by suitable pipes with inlets o', near the bottom of eachwater-leg. A i boiler-front P, having fuel-door p, ash-door, p', andcleaning-out door p2, is secured upon the frontof the boilerand asmoke-box J upon water-arch D.` The spacesvG', adjacent to the tubes F',form flue-passages for the escape of the smoke to the fire-box J, whichis secured upon the rear of the boiler and is provided with smoke-outletJ'. Dalnpers L are hinged vertically inside the smoke-box between theoutlet J and the passages G' upon the plate s3 to circulate the smokeand gases downwardly within the smoke-box during the reguj laroperationof the boiler before they are per- From the outer sides of the chambersA'g upon each section passages E are extendedA mitted to escape. Thedampers are shown closed in Fig. 4, as indicated by dotted lines intheir open position in Fig. 5, which permits the gases to pass directlyfrom the fine-passages in the rear section to the outlet J'. Thedamperspindles are provided with cranks t at their upper end, and a linkm is shown bolted to one of the lcranks and provided with two pins n,adapted to engage an eye lu pon the other crank when the dampers arerespectively opened and closed. The pins are fitted loosely to the eyeto be engaged with it or removed readily.

By bolting the link to one of the cranks it vis secured permanently,while the provision IOO IIO

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of the two pins 'n' adapts it to lock the dampg ers in an open or closedposition without any additional mechanism. The engagement of the pinswith the cranks in the two positions is shown in Figs. 4t and 5,respectively.

By forming the return-dues over the water-chambers A' the upper half ofeach section is materially wider than the lower half, and the smoke-boxis made of corresponding shape, with parallel sides, and to secure therequisite movement of the dampers within such smoke-box when opened, asshown in Fig. 6, the dampers are notched or formed each with a narrowedportion Z' near the lower end. B y this construction the dampers may beextended downward into the narrow part of the smoke-box and the gasesthus forced to a lower point within the smoke-box before they escape tothe outlet J When the dampers are closed, as shown in Fig. 2, the narrowportions Z at the lower end permit a portion of the gases to passupwardly, as indicated by the arrows a', but the remainder are driveninto the course shown by the arrows b in Fig. 6, which carries them overthe entire rear surface of the water-plate s3 upon the rear sectionandthus conveys the heat from the gases to such water-plate. The arrows brepresent the movement of gases when the dampers are closed. Thewater-plate is thus exposed to the heat upon both sides, and the waterin the passages I and tubes F and F3 is thus effectively heated. Adamper-plate CZ closes the space between the passages H and H upon therear section and is provided with a d ust-damper e, operated by rodhaving han?` dle e', asshown in Fig. l. A check-draft damper M is shownupon the smoke-box near the bottom, and grates K are shown pivotedbetween the sections in the usual manner, the water-legs being extendeddownward below the grate-bearings k to inclose the sides of the ash-.boxand absorb the heat therein.

`At the right hand of the central line in Fig. S one of the sections Sis represented` I withthe body C of the fire-arch the full thickness ofthe section, and at the left side of the same line one of theintermediate sections S or S'2 is shown with the body C formed withnotches C2, extended to the side of the water channel C.

' The passages formed by the notches C2 are lettered C2 in Fig. 4, andthe gases rising through the same are guided by the tubes F to theforward endof the boiler through the sections G adjacent to thetubes F,as indibox J as indicated by arrows c2. .With this construction thegases are compelled to traverse all the spaces between the tubes and areretained in contactwith the tubes as long as is desirable to imparttheir heat to the'water. It will be observed by reference to Fig. 10that the water-tubes F2 are of about the same sectional area as thepassages E, and the water-tubes F directly over the chambers A' are ofvery much less area, while the united area of the tubes E and F is lessthan that of the water-leg A. Where the boiler is used for heatingwater, this relation of the parts prevents the water from iiowingupwardly through the outer sides of the section to the outlet at the topof the Water-arch and drives a part of the water naturally into thefirearch, where itis heated and passes upwardly through the middle tubesF. It will also be observed that the chambers A are much greater insectional area than the water-legs, which extend downward, the lire-archwhich, extends laterally, or the tubes E and F', which extend Vupwardlytherefrom. This construction affords a great advantage whether theboiler be used for the heating of water or the generation ofsteam. Inthe latter case the steam rises most rapidly in the tubes F directlyover the fire, producing an upward current in such boiler-tubes, andwhen the water is separated from the steam in the water-arch D itnecessarily flows downward through the cooler tubes F and F at the sidesof the section. As the current entering the water-inlet o" at the bottomof the water-legs is very trifiing in a steam-boiler, the circulation isalmost entirely through the tubes mentioned and the fire-arch, and theenlargement of the chamber A permits the free movement of the waterdownward from the tubes `E and F and its free passage into thefire-arch.

`When t-he boiler is used for heating water and the section is entirelyfilled with such iiuid, a considerable current of the fluid passesupward in the water-legs from the inlets 0 when the external circulationis in operation, and such upward movement interferes .seriously with thenatural downward movement of the current in the side passages E, exceptthe chambers A be provided at the junction of the water-leg and suchpassages to permit the union of such upward and downward currents andtheir free passage into the heated water-arch from which the upwardcurrent is drawn. i

` Where the external circulation of the boiler is cut oif and the upwardcurrent ceases in the water-legs, the water-chambers A perform then thesame function as when generating steam and permit the downward currentfrom the side passages of the section to descend freely to enter thefire arch and move upward through the hotter tubes of the boiler. Suchfree internal circulation prevents the surface of the lsection frombecomi ing overheated when the external circulation is cut off. Theformation of the tire-arch Cl with the water-channel C of the same widthas the tubes F preserves a great part of the internal area of thefire-arch when notched ros IIO

upon the sides, and thus maintains a free circulation within theintermediate sections which require to be thus notched.

Having thus set forth the nature of t-he invention, what is claimedherein isl. In a steam or hot-water boiler having fire-arches withspaces between the same in some of the rear sections for the upwardmovement of the gases and a forward flue over the middle of thefire-arch with backward iiues over the sides of the same, a iiatvertical section with water-legs at the bottom to inclose a lire-box, afire-arch to form the top of the tire-box, a water-arch at the top ofthe section, vertical passages connecting the ends of the water-arch andfire-arch, vertical water- -tubes connecting the water-arch and nre-archbetween such passages, the fire-arch having its upper part the fullthickness of the section, and upon its lower side a central projectingwater-channel of less thickness, and said arch being notched at themiddle upon opposite sides to permit the upward passage of the gasesbetween such sections, substantially as herein set forth.

2. In a steam or hot-water boiler having fire-arches with spaces betweenthe same in some of the rear sections for the upward movement of thegases and a forward flue over the middle of the fire-arch with backwardiiues over the sides of the same, a fiat vertical section havingwater-legs A connected at the top upon their inner sides by thefire-arch C, and provided upon their outer sides at the ends of suchfire-arch with the outwardly-projecting chambers A', passages E extendedupwardly.

froln the chambers A at the outer sides, a water-arch D connecting thetops of such passages, and vertical water-tubes F connecting thewater-chamber and the fire-arch intermediate to thepassage E, as and forthe purpose set forth. f

3. In a steam or hot-water boiler having fire-arches with spaces betweenthe same in some of the rear sections for the upward movement of thegases and a forward flue over the middle of the fire-arch with backwardflues over the sides of the same, a iiat vertical section havingwater-legs A connected at the top upon their inner sides by thefire-arch O, and provided upon their outer sides at the ends of suchlire-arch with the outwardly-projecting chambers A', passages E extendedupwardly from the chambers A at the outer sides, a water-arch Dconnecting the tops of such passages, vertical water-tubes F and F2connecting the water-arch and the lire-arch intermediate to suchpassages, and the tubes F2 at opposite sides of the center having thefull thickness of the section, and the remaining tubes having a lessthickness, as and for the purpose set forth.

4t. In a steam or hot-water boiler having i fire-arches with spacesbetween the same in some of the rear sections for the upward movement ofthe gases and a forward `Iiue over the middle of the fire-arch withbackward fiues over the sides of the same, a flat vertical sectionhaving water-legs A connected at the top upon their inner sides by thefire-arch C, and provided upon their outer sides at the ends of suchfire-arch with the outwardly-projecting chambers A', passages E extendedupwardly from the chambers A at the outer sides, a water-arch Dconnecting the tops of such passages, Vertical water-tubes F and F2connecting the water-arch and the fire-arch intermediate to suchpassages, the tubes F2 at opposite sides of the cent-er having the fullthickness of the section, and the remaining tubes having a lessthickness, and the lire-arch being notched laterally between the tubesF2 to admit the gases upwardly among the tubes F, substantially asherein set forth.

5. In a steam or hot-water boiler, composed of fiat vertical sections asdescribed, the intermediate section having water-legs A withoutwardly-projecting chambers A at the top connected at their innersides by lire-arch C, havingv central waterchannel C upon its underside, passages E extended upwardly from the chambers A' at the outerside, a

water-arch D connecting the tops of such passages, the water-tubes F andF2 connecting the Water-arch and the hre-arch, the watertubes F2 havingthe thickness of the section, and the water-tubes F having the thicknessof thewater-channel, and one side of the firearch notched between thewater-tubes F2 to permit the upward passage of the gases at one side ofthe lire-arch, substantially as herein set forth.

6. In a steam or hot-water boiler, a fiat vertical section havingwater-legs A with outwardly-proj ectin g chambers A at the top connectedat their inner sides by fire-arch C, passages E extended upwardly fromthe chambers A at the outer side, a water-arch D connecting the tops ofthe passages, vertical water-tubes connecting the water-chamber and thefirearch, and the lire-arch having its upper part the full thickness ofthe section,-

and upon its lower side a central projecting water-channel of the samethickness as the central water-tubes, and the fire-arch being notchedlaterally at the middle portion to the thickness of the water tubes andchannel,

substantially as herein set forth.

7. In a steam or hot-water boiler, a rear section consisting of theplate s2 having the water-legs A up'on one side with the chambers Aextended outwardly therefrom, and

portions of a fire-arch C2 projected inwardly l from such chambers, andthe water-arch D I at the top of the water-plate connected with thechambers A' and fire-arch portions C2 by passages E, tubes F and F2,with the smokespaces G between the same, substantially as herein setforth.

8. In a steam or hot-water boiler, a rear section consisting of theplate S2 having the water-legs A upon one side with the chambers Aextended outwardly therefrom, and

portions of a fire-arch C2 projected inwardly IOO IIO

' from such chambers, and the water-arch D at the top of the water-plateconnected with the chambers A and fire-arch portions C2 by passages E,tubes F and F2, with the smokespaces G between the same, the passages Hconnecting water-legs A, and the vertical passages I within the plate s2connecting the passage H and arch D, substantially as herein set forth.

9, In a steam or hot-water boiler, a rear section consisting of theplate s3 having the water-legs A upon one side with the chambers Aextended outwardly therefrom, and portions of a fire-arch C2 projectedinwardly from such chambers, and the water-arch D at the top of thewater-plate connected with the chambers A/ and fire-arch portions C2 bypassages E, tubes F and F2, with the smokespaces G between the same, thepassage H connecting water-legs A at the grate-level with opening` belowthe same between the water-legs, and the vertical passages I within theplate connecting the passage H with the water-arch D, substantially asherein set forth.

10. In a steam or hot-water boiler, the flat vertical section havingwater-legs A connected at the top upon their inner sides by theiire-arch C, and provided upon their outer sides at the ends of suchfire-arch with the outwardly-projecting chambers A', passages E of lesssectional area than the water-legs extended upwardly from the chambers Aat the outer sides of the same, a Water-arch D of greater sectional areathan the passages E connecting the tops of such passages, and ver` ticalwater-tubes connecting the water-chamber and the tire-arch,substantially as herein set forth.

ll. In a steam or hot-water boiler, the iiat vertical section havingwater-legs Apwith outwardly-projecting chambers A at the top connectedat their inner sides by fire-arch C, having central water-channel C uponits under side, passages E of less sectional area than the Water-legsextended upwardly from the chambers A at the outer side, a water-arch D,of greater sectional area than the passages E connecting the tops ofsuch passages, and vertical water-tubes of the same thickness as thewater-channel C connecting the waterchamber and the fire-arch, as andfor the purpose set forth.

12. In a steam or hot-water boiler, the flat vertical section havingwater-legs A with outwardly-projecting chambers A' at the top connectedat their inner sides by fire-arch C, having central waterchannel C uponits under side, the passages E ofV less sectional area than thewater-legs extended upwardly, from the chambers A at the outer side, awater-arch D, of .greater sectional area than the passages E connecti-ngthe tops of such passages, and vertical water-tubes of the samethickness as the water-channel C connecting the water-chamber and thenre-arch, and the nre-arch being notched at the middle to the sides ofthe water-channel C to permit th'e upward passage of the gases between aseries of such sections, substantially as herein set forth.-

13. In a steam or hot-water boiler, the iat vertical section havingwater-legs A with outwardly-proj ectin g chambers A' at the topconnected at their inner sides by fire-arch C, having centralwater-channel C upon its under side, `passages E of less sectional areathan the water-legs extended upwardly from the chambers A' at the outerside, a waterarch D, of greater sectional area than the passages Econnecting the tops of such passages, the water-tubes F and F2connecting the water-chamber and fire-arch, the watertubes F2having thethickness of the section, and the water-tubes F having the thickness ofthe water-channel C', and the side of the fire-arch being notchedbetween the watertubes F2 to permit the upward passage of the gases,substantially as herein set forth.

14. A vertical sectional boiler comprising a series of flat sectionshaving the vertical water-legs A with outwardly-projecting chambers Alat the top connected at their inner sides by tire-arch C and having thepassages E of the same .thickness as the section eX- tended upwardlyfrom the chambers A' at the outer side, with water-arch I) connectingthe tops of such passages, and vertical watertubes connecting thewater-arch and the {irearch, substantially as herein set forth.

15. A vertical sectional boiler comprising a series of flat sectionshaving the vertical water-legs A with outwardly-projecting chambers A atthe top connected at their inner sides by fire-arch C and having thepassages E of the same thickness as the section and of less sectionalarea than the water-legs eX- tended upwardly from the chambers Al at theouter side, with water-arch D of greater sectional area than thepassages E connect- -ing the tops of such passages, and verticalwater-tubes connecting the water-arch and the fire-arch, substantiallyas herein set forth.

16. A vertical sectional boiler comprising a series of iiat sectionshaving the veiltical water-legs A with outwardly-projecting chambers Aat the top connected at their inner sides by fire-arch C and having thepassages E of the same thickness as the section and of less sectionalarea than the water-legs extended upwardly from the chambers A' at theouter side, with water-arch D of greater sectional area than thepassages E connecting the tops of such passages, the verticalwater-tubes F2 of the same thickness as the section and the samesectional area as the passages E, and the water-tubes F having lessthickness than the section, substantially as herein set forth.

17. A vertical sectionalboiler comprising a series of flat sectionshaving the vertical water-legs A with outwardly-projecting chambers A'at the top connected attheir inner sides by the fire-arch C havingwater-channel IOO IOS v IIO C', and having the passages E of the samethickness as the section and of less area than the water-legs, extendedupward from the chambers A' at the outer side, with waterarch D ofgreater sectional area than the passages E connecting the tops of suchpassages, the vertical water-tubes F2 of the same thickness as thesection, the water-tubes F and F' of the same thickness as thewater-channel C', and the water-arch between the tubes F2 being notchedupon the side, as and for the purpose set forth.

18. In a boiler comprising a series of fiat vertical sections havingeach the water-legs A, water-chambers A', fire-arch C, passages E,water-arch D, and water-tubes connecting the fire-arch and water-arch,the combination, with the sections S having the fire-archl the fullthickness of the section, of the intermediate and rear sections S', S2and S3 having the tire-arch notched to perlnit the upward movement ofthe gases, and the rear section formed with the plate s3, and providedupon its upper part with the openings G', the whole arranged andoperated substantially as herein set forth.

19. In a boiler comprising a series of flat vertical sections havingeach the water-legs A, water-chambers A', fire-arch C, passages E,water-arch D, and water-tubes connecting the fire-arch and water-arch,the combination, with the sections S having the fire-arch the fullthickness of the section, of the intermediate and rear sections S', S2and S3 having the fire-arch'notched to permit the upward movement of thegases, and the rear section formed with the plate s3, having upon itsupper part the openings G' and upon its lower part the transversewater-passages H and H' with openin gs for dust-flue between suchpassages, the whole arranged and operated substantially as herein setforth.

20. In a boiler comprising a series of flat vertical sections havingeach the water-legs A, water-columns A', fire-arch C, passages E,water-arch D, and water-tubes connecting the fire-arch and water-arch,the combination, with the sections S having the fire-arch the fullthickness of the section, of the intermediate and rear sections S', S2and S3 having the fire-arch notched to permit the upward movement of thegases, and the rear section formed with the plate s3, having upon itsupper part the openings G' and upon its lower part the transverseWater-passages H and H' with the plate d secured thereon and thedust-damper c tted to an opening in such plate, and a smoke-box fittedto the section S3 and inclosing the passages G' and dust-damper,substantially as herein set'forth.

21. A vertical sectional boiler comprising a series of flat sectionshaving the vertical water-legs A with outwardly-projecting chambers A'at the top connected at their inner sides by fire-arch C and having thepassages E of the same thickness as the section eX- tended upwardly fromthe chambers A' at the outer side, the water-archD of the same thicknessas the section connecting the tops of such passages, verticalwater-tubes connecting the water-arch to the fire;arch, the notches C2in the fire-arches of the rear sections, and certain of the water-tubesmade the full thickness of the section, and the remainder of lessthickness, to form a forward iiue over the rebox and backward fines atthe sides of the section over the chambers A', substantially as hereinset forth.

22. In a boiler comprising a series of fiat vertical sections of greaterWidth upon the upper than upon the lower part, with a rear sectionhaving the plate s3 with flue-openings G' in the upper part, thecombination, with such sections, of the smoke-box .I of greater width inthe upper than in the lower part, as set forth, fitted to the rearsection to inclose the said flue-openings, and provided withsmoke-outlet in the middle at the upper part, and4 having the dampers Lpivoted in the smoke-box between such outlet and flue-openings, andprovided with the narrowed portions Z' at the lower end extendeddownward into the narrow part of the smoke-box, substantially as hereinshown and described.

23. In a boiler comprising a series of fiat vertical sections with arear section having the plate S3 with flue-openings G' in theupper'part, the combination, with such sections, of the smoke-box Jfitted to the rear section to inclose the said flue-openings, andprovided with smoke-outlet upon the center line, and having the dampersL pivoted in the smoke-box between such outlet and flue-openings, Withthe cranks Z attached to the spindles, and the link m bolted to one ofsaid cranks and provided with two pins n fitted interchangeably anddetachably to an eye upon the other crank to adjust the dampers open andshut respectively, substantially as herein set forth.

24. A vertical sectional boiler comprising a series of flat sectionshaving the vertical water-legs A with outwardly-projecting chambers A'at the top connected at their inner sides by fire-arch C, and havingpassages E of less sectional area than the water-legs extended upwardlyfrom the chambers A' at the outer side, with water-arch D of greatersectional area than the passages E connecting the tops of such passages,and vertical watertubes connecting the water-arch with the tops -of thechambers A' and the fire-arch, the

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